I'm scared of swinging fast

Just when I think I'm serving slice serves and kick serves with great rhythm, I mis-hit one (usually into someone) and begin feeling scared to swing fast. I don't do it that often (maybe once every 3 matches), but after hitting one, the thought of mis-hitting again and hurting someone really shakes my concentration and the rest of my game starts to breakdown.

It seems like the harder I swing, the more likely it is likely to result in this mis-hit. It also only happens on slice or kick serves. I think this is because it's hit with an 'open face' on impact, thus stays on the strings for longer(?). I think I've tried to explain this before, but basically what happens is, it seems to roll off the strings TWICE. Actually it could be coming off the strings, then hitting the inside of the frame before the ball got to escape from the area. Hence, when I swing fast, this happens. I guess what could be happening is: the ball comes off the strings once, and then with my follow through I hit it again. Sounds weird, I know. And it often results in a totally wild shot which travels more to the right than I wanted it to, usually with PLENTY of slice/underspin to make it curve left at the end (I am right handed). I think when this happens, I have the ball toss above my head. What could I be doing wrong? Could I be swinging up too much? Getting in the way of the ball's path? One reassuring thing is that I've seen other players who have big serves and fast swings do it as well.

Anyway, what I want to ask is:
1) Do any of you know what the heck I am on about
2) Do any of you do this as well
3) Do any of you know what causes this exactly?
4) Do any of you have any hints to cut down on these weird mis-hits.

I wish I could elaborate on my problem but I really have no idea what the heck is going on. Thank you!

When you serve (any serve) does your palm face up just after you toss the ball? where does it end up facing just before you start to move your arm to hit the ball?

The other thing is your most likely moving yoru eyes off the ball right before you hit it. Or your head is throwing off your swing pattern because it is dropping downward right before impact. It could be within a fraction of a second. But that is enough to alter your swing.

Try this and see what I mean: Hold your arm straight up as high as you can. With your head straight drop your head down while holding your arm straight up. Can you see what happens? You arm drops with your head.

So what might be happening is your brain sees a mental picture of the path it needs to take but the eyes dont give it enough feedback to varify if it is correct. The head drops down and the arm continues on an altered path - which produces errors or mis-hits.

The solution? Glad you asked, and it is a good one. One word - PRACTICE. Yes, you must practice practice practice.

Practice keeping your head up and watching the blur of your arm go by. Practice increasing your swing speed. Practice your spins until they all go in! Practice to remove the hee-bee-gee-bee's when the match gets tight or you feel a little shaken.

I love hitting those 'Jack Framers'. It usually happens to me when I'm trying to put mondo spin on one of my serves.

I think it happens because of the racket path. The extreme spin often requires extreme brushing, and because of this the initial hit from the strings won't move the ball forward enough before the edge the racket hits it.

I just try to remember to put forward momentum on the ball. Even though it's going to be spinning heavily, it still needs to have some forward impetus. Hit THROUGH the ball a little more.

I also focus on my toss. When it happens I usually notice that my toss is not far enough into the court.

Bungalo Bill, gza, thank you! I went out to play this morning and deliberately tried to hit those shots, and I think I may have figured out what the problem is. As mentioned, I sometimes do drop my head, and my arm moves in a different direction then intended. But this is what I think may be the problem:

hitting the left hand edge of the racquet strings.

When concentrating on spinning the ball, I tend to 'wrap' around the ball, and thus clipping the ball with the left edge of the racquet strings, which then rolls onto the frame. Taking this into account, I started to hit spin balls with me conciously trying to hit the ball with the RIGHT edge of the racquet, and all went smooth!!!

I am so happy I have figured out what was wrong. Concentrating on excess spin and wrapping the ball on my frame without looking at the contact point properly. Thank you guys!

Actually I am more interested in your hitting arm not the tossing arm. Many times players do a little quick knee bendand as they come up they drop the racquet over their shoulders as the gaze up towards the tossed ball and point their palm towards the sky, then step forward and push the ball.

ok, without seeing it, just make sure your not flooping your wrist back then going forward to hit the ball. By the time your ready to send the racquet upward, your palm should be facing your ear and not up toward the sky.